I noticed old threads related to some users having problems with changing hotkeys for language change to those that use Shift + Alt L, etc.
So I decided to share my way, which allows you to change settings via a command in the terminal:
Forward switch:
gsettings set org.gnome.desktop.wm.keybindings switch-input-source "['<Shift>Alt_L']"
Backward switch:
gsettings set org.gnome.desktop.wm.keybindings switch-input-source-backward "['<Alt>Shift_L']"